This is something that I have actually talked about with several people. Each time I find myself going back to the same example, Evrquest's Alternate Advancement system or AA. This was something that allowed players to gain xp that would net he/she points to spend to further improve their characters beyond just getting the best gear possible. http://everquest.allakhazam.com/db/aaskills.html. This link should give people a basic understanding of the system.

In every MMO that I have played since EQ, I have wanted to see a similar system in those games. Consider the amount of times players run dungeons, fates, leves, raids and have the xp earned in that time spent is essentially deleted from the system. Why not have it go some where? Why not give players a reason to keep endlessly grinding dungeons, fates, leves, and raids at max level?